Derby County defender Russell Anderson is likely to be out for another month after his return to full training was delayed.
Anderson has struggled with injuries this season and tore a groin muscle against Leeds United on the opening day of the campaign.
He returned to make three brief substitute's appearances, but has not played since mid-November due to a hamstring problem.
The 32-year-old was due to resume full training on Monday, but he has now picked up a calf strain which will keep him out for another few weeks.
"It's a blow for Russell," Derby boss Nigel Clough told the club's official website.
"I feel for him. He has had such a frustrating time this season with different, niggling injuries.
"He will be out for a few more weeks, so it could be up to four weeks before he is in a position to join full training again."